Grant Agreements - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended		3 Months Ended		9 Months Ended
	Jan. 13, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reserve for remaining estimated manufacturing expenses		$ 146,111		$ 146,111		$ 146,111		$ 489,090
Other current assets		4,800		4,800		4,800
VIR Biomedical Advanced Research and Development Authority | Grant revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from grants				2,900		29,000
Human Immunodeficiency Virus ('HIV') Grant | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Grant awarded amount. maximum		49,900		49,900		49,900
Vaccinal Antibody Grant | Grant revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from grants				3,800	$ 2,800	10,500	$ 7,400
Vaccinal Antibody Grant | Bill And Melinda Gates Foundation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock shares purchased (in shares)	881,365
Common stock, shares purchased price (in USD per share)	$ 45.38
Common stock, shares purchased, aggregate purchase price	$ 40,000
Common stock, shares issued, fair market value	$ 28,500
Closing stock price (in USD per share)	$ 37.65
Premium received	$ 11,300
Deferred revenue		15,300		15,300		15,300		15,500
Reserve for remaining estimated manufacturing expenses		9,200		9,200		9,200		$ 7,700
BARDA
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Base period funding			$ 55,000
New funding		50,100		50,100		50,100
Potential future reimbursement		60,900		60,900		60,900
Total Awarded Amount						116,300
BARDA | development of VIR-7229 through a Phase 1 clinical trial
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
New funding		40,000		40,000		40,000
BARDA | New Monoclonal Antibody Discovery
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
New funding		10,100		$ 10,100		$ 10,100
BARDA | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Maximum grant amount to be received			$ 1,000,000
Additional funding		$ 11,200